In technical installations the task often arises of an object at rest in the installation having to be picked up by a transport device. For this purpose the object has one—or as a rule also a number—of pickup points, at which the transport device can pick up the object. In particular if this pickup is to take place automatically the precise spatial location of the pickup point must be established.
An EAF (Electric Arc Furnace) installation is cited below as an example of an installation. The object is then a scrap basket able to be filled with steel scrap to be smelted, which is at rest for example on a scrap conveyor, e.g. a rail vehicle, or at another transfer point. The transport device is a charging crane. The pickup points are then transport eyes on the scrap basket into which the charging crane engages with corresponding transport hooks in order to lift the scrap basket and transport it.
The picking up of the scrap basket from a scrap conveyor or from another transfer point by the charging crane is a part of the charging process. It is known that this process can be carried out manually by a crane driver and without automation or measurement technology. This is done by remote control, i.e. by a remote control from the installation floor or by desk operation by the furnace attendant or as a mobile operation from a crane cabin. The operation is always undertaken within sight by the crane driver, e.g. by direct optical control or camera-based by observing a live video image. It is not necessary here to determine the position of the scrap basket or of its pickup point.
Automatic scrap charging into an electric arc furnace would now be desirable. The plan here is the automated charging basket pickup by the charging crane, the automated charging basket transport by the charging crane to the electric arc furnace, the automatic charging into the furnace vessel and also the automated transport of the charging basket back to the charging conveyor or to another transfer point. The discussion here deals merely with a subproblem of this field, namely the determination of the actual spatial position of the pickup point of the scrap basket. The spatial location determined can then for example be supplied to the control of the charging crane which can then move automatically to the corresponding position in order to pick up the scrap basket in a precisely targeted manner.
The object would be achievable for example by a 3D laser scan or a by live camera monitoring of the installation or by a combination of the two methods. Such a system would have to be installed in the installation in order for example to determine the actual position of the pickup point in a fixed coordinate system of the installation. Expensive hardware and measurements (3D laser scanner) or complex video evaluation with the expensive special hardware (camera image evaluation) are necessary for this purpose. Such a solution would therefore be complex and expensive.
EP 1519372 A2 discloses a system and a method for positioning a robot.
DE 212009000055 U1 describes a facility for improving handling devices such as multi-axis industrial robots.
DE 3302177 A1 describes a method and a device for automatic handling or processing or for automatic assembly of objects.